1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * LED driver for WM8350 driven LEDS.
4 *
5 * Copyright(C) 2007, 2008 Wolfson Microelectronics PLC.
6 */
7
8 #include <linux/kernel.h>
9 #include <linux/platform_device.h>
10 #include <linux/leds.h>
11 #include <linux/err.h>
12 #include <linux/mfd/wm8350/pmic.h>
13 #include <linux/regulator/consumer.h>
14 #include <linux/slab.h>
15 #include <linux/module.h>
16
17 /* Microamps */
18 static const int isink_cur[] = {
19 4,
20 5,
21 6,
22 7,
23 8,
24 10,
25 11,
26 14,
27 16,
28 19,
29 23,
30 27,
31 32,
32 39,
33 46,
34 54,
35 65,
36 77,
37 92,
38 109,
39 130,
40 154,
41 183,
42 218,
43 259,
44 308,
45 367,
46 436,
47 518,
48 616,
49 733,
50 872,
51 1037,
52 1233,
53 1466,
54 1744,
55 2073,
56 2466,
57 2933,
58 3487,
59 4147,
60 4932,
61 5865,
62 6975,
63 8294,
64 9864,
65 11730,
66 13949,
67 16589,
68 19728,
69 23460,
70 27899,
71 33178,
72 39455,
73 46920,
74 55798,
75 66355,
76 78910,
77 93840,
78 111596,
79 132710,
80 157820,
81 187681,
82 223191
83 };
84
85 #define to_wm8350_led(led_cdev) \
86 container_of(led_cdev, struct wm8350_led, cdev)
87
wm8350_led_enable(struct wm8350_led * led)88 static int wm8350_led_enable(struct wm8350_led *led)
89 {
90 int ret = 0;
91
92 if (led->enabled)
93 return ret;
94
95 ret = regulator_enable(led->isink);
96 if (ret != 0) {
97 dev_err(led->cdev.dev, "Failed to enable ISINK: %d\n", ret);
98 return ret;
99 }
100
101 ret = regulator_enable(led->dcdc);
102 if (ret != 0) {
103 dev_err(led->cdev.dev, "Failed to enable DCDC: %d\n", ret);
104 regulator_disable(led->isink);
105 return ret;
106 }
107
108 led->enabled = 1;
109
110 return ret;
111 }
112
wm8350_led_disable(struct wm8350_led * led)113 static int wm8350_led_disable(struct wm8350_led *led)
114 {
115 int ret = 0;
116
117 if (!led->enabled)
118 return ret;
119
120 ret = regulator_disable(led->dcdc);
121 if (ret != 0) {
122 dev_err(led->cdev.dev, "Failed to disable DCDC: %d\n", ret);
123 return ret;
124 }
125
126 ret = regulator_disable(led->isink);
127 if (ret != 0) {
128 dev_err(led->cdev.dev, "Failed to disable ISINK: %d\n", ret);
129 ret = regulator_enable(led->dcdc);
130 if (ret != 0)
131 dev_err(led->cdev.dev, "Failed to reenable DCDC: %d\n",
132 ret);
133 return ret;
134 }
135
136 led->enabled = 0;
137
138 return ret;
139 }
140
wm8350_led_set(struct led_classdev * led_cdev,enum led_brightness value)141 static int wm8350_led_set(struct led_classdev *led_cdev,
142 enum led_brightness value)
143 {
144 struct wm8350_led *led = to_wm8350_led(led_cdev);
145 unsigned long flags;
146 int ret;
147 int uA;
148
149 led->value = value;
150
151 spin_lock_irqsave(&led->value_lock, flags);
152
153 if (led->value == LED_OFF) {
154 spin_unlock_irqrestore(&led->value_lock, flags);
155 return wm8350_led_disable(led);
156 }
157
158 /* This scales linearly into the index of valid current
159 * settings which results in a linear scaling of perceived
160 * brightness due to the non-linear current settings provided
161 * by the hardware.
162 */
163 uA = (led->max_uA_index * led->value) / LED_FULL;
164 spin_unlock_irqrestore(&led->value_lock, flags);
165 BUG_ON(uA >= ARRAY_SIZE(isink_cur));
166
167 ret = regulator_set_current_limit(led->isink, isink_cur[uA],
168 isink_cur[uA]);
169 if (ret != 0) {
170 dev_err(led->cdev.dev, "Failed to set %duA: %d\n",
171 isink_cur[uA], ret);
172 return ret;
173 }
174
175 return wm8350_led_enable(led);
176 }
177
wm8350_led_shutdown(struct platform_device * pdev)178 static void wm8350_led_shutdown(struct platform_device *pdev)
179 {
180 struct wm8350_led *led = platform_get_drvdata(pdev);
181
182 led->value = LED_OFF;
183 wm8350_led_disable(led);
184 }
185
wm8350_led_probe(struct platform_device * pdev)186 static int wm8350_led_probe(struct platform_device *pdev)
187 {
188 struct regulator *isink, *dcdc;
189 struct wm8350_led *led;
190 struct wm8350_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
191 int i;
192
193 if (pdata == NULL) {
194 dev_err(&pdev->dev, "no platform data\n");
195 return -ENODEV;
196 }
197
198 if (pdata->max_uA < isink_cur[0]) {
199 dev_err(&pdev->dev, "Invalid maximum current %duA\n",
200 pdata->max_uA);
201 return -EINVAL;
202 }
203
204 isink = devm_regulator_get(&pdev->dev, "led_isink");
205 if (IS_ERR(isink)) {
206 dev_err(&pdev->dev, "%s: can't get ISINK\n", __func__);
207 return PTR_ERR(isink);
208 }
209
210 dcdc = devm_regulator_get(&pdev->dev, "led_vcc");
211 if (IS_ERR(dcdc)) {
212 dev_err(&pdev->dev, "%s: can't get DCDC\n", __func__);
213 return PTR_ERR(dcdc);
214 }
215
216 led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL);
217 if (led == NULL)
218 return -ENOMEM;
219
220 led->cdev.brightness_set_blocking = wm8350_led_set;
221 led->cdev.default_trigger = pdata->default_trigger;
222 led->cdev.name = pdata->name;
223 led->cdev.flags |= LED_CORE_SUSPENDRESUME;
224 led->enabled = regulator_is_enabled(isink);
225 led->isink = isink;
226 led->dcdc = dcdc;
227
228 for (i = 0; i < ARRAY_SIZE(isink_cur) - 1; i++)
229 if (isink_cur[i] >= pdata->max_uA)
230 break;
231 led->max_uA_index = i;
232 if (pdata->max_uA != isink_cur[i])
233 dev_warn(&pdev->dev,
234 "Maximum current %duA is not directly supported,"
235 " check platform data\n",
236 pdata->max_uA);
237
238 spin_lock_init(&led->value_lock);
239 led->value = LED_OFF;
240 platform_set_drvdata(pdev, led);
241
242 return led_classdev_register(&pdev->dev, &led->cdev);
243 }
244
wm8350_led_remove(struct platform_device * pdev)245 static int wm8350_led_remove(struct platform_device *pdev)
246 {
247 struct wm8350_led *led = platform_get_drvdata(pdev);
248
249 led_classdev_unregister(&led->cdev);
250 wm8350_led_disable(led);
251 return 0;
252 }
253
254 static struct platform_driver wm8350_led_driver = {
255 .driver = {
256 .name = "wm8350-led",
257 },
258 .probe = wm8350_led_probe,
259 .remove = wm8350_led_remove,
260 .shutdown = wm8350_led_shutdown,
261 };
262
263 module_platform_driver(wm8350_led_driver);
264
265 MODULE_AUTHOR("Mark Brown");
266 MODULE_DESCRIPTION("WM8350 LED driver");
267 MODULE_LICENSE("GPL");
268 MODULE_ALIAS("platform:wm8350-led");
269